Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature.

Verdant Sun's Avatar

Whenever Verdant Sun's Avatar or another creature you control enters, you gain life equal to that creature's toughness.

Path of Discovery

Whenever a creature you control enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Thicket Elemental

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Thicket Elemental enters, if it was kicked, you may reveal cards from the top of your library until you reveal a creature card. If you do, put that card onto the battlefield and shuffle all other cards revealed this way into your library.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Yarok, the Desecrated

Deathtouch, lifelink
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Diabolic Servitude

When Diabolic Servitude enters, return target creature card from your graveyard to the battlefield.
When the creature put onto the battlefield with Diabolic Servitude dies, exile it and return Diabolic Servitude to its owner's hand.
When Diabolic Servitude leaves the battlefield, exile the creature put onto the battlefield with Diabolic Servitude.

Rune-Scarred Demon

Flying
When Rune-Scarred Demon enters, search your library for a card, put it into your hand, then shuffle.

Dismal Backwater

Dismal Backwater enters tapped.
When Dismal Backwater enters, you gain 1 life.
{T}: Add {U} or {B}.

Noxious Gearhulk

Menace
When Noxious Gearhulk enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Mortuary Mire

Mortuary Mire enters tapped.
When Mortuary Mire enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Vedalken Orrery

You may cast spells as though they had flash.

Priest of Gix

When Priest of Gix enters, add {B}{B}{B}.

Fathom Mage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever a +1/+1 counter is put on Fathom Mage, you may draw a card.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Barren Moor

Barren Moor enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Mazirek, Kraul Death Priest

Flying
Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

World Shaper

Whenever World Shaper attacks, you may mill three cards.
When World Shaper dies, return all land cards from your graveyard to the battlefield tapped.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Venser, Shaper Savant

Flash
When Venser, Shaper Savant enters, return target spell or permanent to its owner's hand.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Fetid Pools

({T}: Add {U} or {B}.)
Fetid Pools enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Simic Signet

Pondering Mage

When Pondering Mage enters, look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Reclamation Sage

When Reclamation Sage enters, you may destroy target artifact or enchantment.

The Mending of Dominaria

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Mill two cards, then you may return a creature card from your graveyard to your hand.
III — Return all land cards from your graveyard to the battlefield, then shuffle your graveyard into your library.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature.

Spellseeker

When Spellseeker enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Thief of Sanity

Flying
Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Trophy Mage

When Trophy Mage enters, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Temple of Deceit

Temple of Deceit enters tapped.
When Temple of Deceit enters, scry 1.
{T}: Add {U} or {B}.

Tishana, Voice of Thunder

Tishana, Voice of Thunder's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
When Tishana enters, draw a card for each creature you control.

Faerie Impostor

Flying
When Faerie Impostor enters, sacrifice it unless you return another creature you control to its owner's hand.

Ob Nixilis, the Fallen

Landfall — Whenever a land you control enters, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Wall of Blossoms

Defender
When Wall of Blossoms enters, draw a card.

Retreat to Hagra

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +1/+0 and gains deathtouch until end of turn.
• Each opponent loses 1 life and you gain 1 life.

Yarok's Wavecrasher

When Yarok's Wavecrasher enters, return another creature you control to its owner's hand.

Salvager of Secrets

When Salvager of Secrets enters, return target instant or sorcery card from your graveyard to your hand.

Dimir Signet

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land you control enters, you gain 1 life.

Sporemound

Landfall — Whenever a land you control enters, create a 1/1 green Saproling creature token.

Yarok's Fenlurker

When Yarok's Fenlurker enters, each opponent exiles a card from their hand.
{2}{B}: Yarok's Fenlurker gets +1/+1 until end of turn.

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Dimir Guildgate

Dimir Guildgate enters tapped.
{T}: Add {U} or {B}.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Snapcaster Mage

Flash
When Snapcaster Mage enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Hydroid Krasis

When you cast this spell, you gain half X life and draw half X cards. Round down each time.
Flying, trample
Hydroid Krasis enters with X +1/+1 counters on it.

Diluvian Primordial

Flying
When Diluvian Primordial enters, for each opponent, you may cast up to one target instant or sorcery card from that player's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.

Bramble Sovereign

Whenever another nontoken creature enters, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.

Grazing Gladehart

Landfall — Whenever a land you control enters, you may gain 2 life.

Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Tribute Mage

When Tribute Mage enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Temple of Mystery

Temple of Mystery enters tapped.
When Temple of Mystery enters, scry 1.
{T}: Add {G} or {U}.

Khalni Heart Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on Khalni Heart Expedition.
Remove three quest counters from Khalni Heart Expedition and sacrifice it: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Ezuri, Claw of Progress

Whenever a creature you control with power 2 or less enters, you get an experience counter.
At the beginning of combat on your turn, put X +1/+1 counters on another target creature you control, where X is the number of experience counters you have.

Blighted Woodland

{T}: Add {C}.
{3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Sepulchral Primordial

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When Sepulchral Primordial enters, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Fertilid

Fertilid enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Primordial Sage

Whenever you cast a creature spell, you may draw a card.

Crucible of Worlds

Soul of the Harvest

Trample
Whenever another nontoken creature you control enters, you may draw a card.

Golgari Signet

Gaea's Cradle

{T}: Add {G} for each creature you control.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Phyrexian Ingester

Imprint — When Phyrexian Ingester enters, you may exile target nontoken creature.
Phyrexian Ingester gets +X/+Y, where X is the exiled creature card's power and Y is its toughness.

Temple of Malady

Temple of Malady enters tapped.
When Temple of Malady enters, scry 1.
{T}: Add {B} or {G}.

Vinelasher Kudzu

Landfall — Whenever a land you control enters, put a +1/+1 counter on Vinelasher Kudzu.

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.